Impact absorbing apparatus



`uly 25, 1967 .1. T. SMITH IMPACT ABSORBING APPARATUS y 2 Sheets-Sheet 2 Filed sept. 1o, 1964 INV NTOR.

United States Patent "p 3,332,364 IMPACT ABSORBING APPARATUS lames T. Smith, Wilmette, lll., assignor to Keystone Railway Equipment Company, Chicago, Ill., a corporation f Delaware Filed Sept. 10, 1964, Ser. No. 395,390 3 Claims. (Cl. 10S- 454) The present invention relates to an impact absorbing apparatus, and in particular to an improved impact absorbing apparatus for railway rolling stock.

Railway rolling stock, particularly freight cars, is subject to appreciable impacts in switch and classification yards where the trains are both broken up and made up. It is customary to attempt to limit the speed of the free rolling oars so that at the time of impact with another car the speed is not more than three or four miles per hour. However, this is not always possible and speeds as high as ten, twelve, or more miles per hour are known. Also, coupling speeds of ten, twelve, or more miles per hour are not uncommon in making up the train or picking up cars from sidings, loading docks, and the like.

Tremendous thought, study, and research have been given to the problem of protecting the load or lading against damage from the impacts given to a fully or partially loaded freight car during coupling. The character of the lading itself usually dictates the best way it should be secured in a car. Some of the securing techniques provide for a controlled and limited movement of the load within the car to absorb the coupling or similar impact without damage to the load.

The draft gear connected to the coupler absorbs a part of the shock, but its effectiveness is limited by the severe limitation on the movement of the coupler relative to the remainder of the car. This movement is about two and three-quarter inches so as to minimize the amount of slack in a train that has to be taken up on starting and absorbed on stopping.

It has been proposed to interpose an impact absorbing cushion in the car between the draft gear and the lading which will permit the lading to move up to a certain distance on impact and thereafter be restored to its original or normal position. Alternatively, the impact absorbing cushion is interposed between the center sill for buff and draft and the underframe of the railway car. These cushions are of various designs and permit maximum movement from as little as eight inches up to as much as 40 inches. It is thought by some that the longer the cushion movement the greater the protection afforded to the lading. A principal dilculty with long cushion movement is the projection of the center sill for bull and draft beyond the end of the car a distance of 40 inches more than normal. This of course projects the coupler 40 inches greater beyond the end of the car than theretofore. When cars of this type are coupled into a train, particularly when coupled to each other, dilliculties are encountered in sharp curves and it has been found necessary to prevent the routing of such cars over trackage which has such curves. This long projecting sill also makes coupling of these cars extremely diflicult unless the coupling is done on straight track.

The present invention is concerned with improvements in impact absorbing cushions whereby whatever advantages exist in long movement may be retained with a cushion movement which is appreciably shorter.

It is therefore a principal object of the present invention to provide a hydraulic impact absorbing cushion be- 3,332,354 Patented July 25, 1967 tween the draft and gear and the lading in fa freight car, having a movement less than half the maximum movement of long movement devices now available while retaining the load protecting advantages of such devices.

Another object is to provide a hydraulic impact absorbing cushion between the draft gear andthe lading in a freight car, wherein the maximum lading movement is less than 20 inches.

Another object is to provide a hydraulic impact absorbing cushion incorporating a hydraulic cylinder and a separate reservoir, interconnected by a piston rod fixed to the reservoir and to a piston slidable in the cylinder, with a flow metering bore through the piston rod and an excess fluid compensating means in the reservoir.

Another object is to provide a hydraul-ic impact absorbing cushion incorporating a hydraulic cylinder and a separate reservoir, interconnected by a piston rod fixed to the reservoir and to a piston slidable in the cylinder, with a flow metering bore through the piston rod and excess fluid compensating compressible sealed hollow air containing rings in the reservoir.

Other'objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings, wherein FIG. l is a fragmentary perspective view of the underframe of la `railway car, partly broken away to illustrate the manner of mounting the impact absorbing apparatus of the present invention between the center sill for buil and draft and the underframe;

FIG. 2 is a vertical sectional View on an enlarged scale, taken along the line 2-2 of FIG. 1, looking in the direction of the arrows;

FIG. 3 is fa medial plan sectional view taken through the impact absorbing apparatus of the present invention, showing the apparatus in normal position;

FIG. 4 is a transverse sectional view taken through the fluid reservoir along the line 4-4 of FIG. 3, looking in the direction of the arrows; and

FIG. 5 is a view similar to FIG. 3, on a smaller scale, showing the impact absorbing apparatus in partially collapsed position.

Referring to FIG. 1, it can be seen that an impact absorbing device 10 is interposed between a slidable center sill 12 for bull and draft and an underframe center sill 14 Within which it is mounted. Underframe 16 includes the conventional side sills 18, bolsters 20 (only one of which is shown), cross bearers 22, and other transverse bracing 24. The bolsters are mounted on conventional trucks which ride on the rails, and the underframe 16 supports the conventional box or other lading containing structure. Conventional couplers and draft gear (not shown) are carried by the slidable center sill 12 and the extreme ends thereof.

The slidable center sill 12 as seen in FIG. 2 has an inverted channel-shaped configuration with side flanges 26 which slide on cross plates 2S carried by the various transverse frame members.

The impact absorbing device 10 includes a cylinder 30 having a cylinder head 32, and a reservoir 34 having a head 36 with a piston rod 38 extending between the cylinder 3i) and the reservoir 34. A heavily loaded spring 40 (6000 pounds, for example) extends between the cylinder head 32 and the reservoir 34 urging them apart and also urging the cylinder head 32 and the reservoir head 36 into engagement with stop lugs 42 carried on the slidable center sill 12 and into engagement with force transmitting stop members 44 carried on the underframe 16 of the car.

When there is relative movement between the center sill 12 and the frame center sill 14, one or the other of the heads 32 and 36 is moved away from the stop lugs 42 while the other head is moved away from .the underframe stop member 44. The normal position is that as shown in FIGS. 1 and 3 lwhile an impact transmitting position from the right coupler is shown in FIG.

The piston rod 38 projects into the cylinder 30 through a suitable packing 46 in a rod end cylinder head 45, and is connected to a piston 48 slidable in the cylinder. The piston rod 38 extends to the head end of the piston 48 and has a bore 50 extending throughout its length so as to communicate the head end of the cylinder 30 with the rod end and with the reservoir 34. The piston rod 38 is therefore provided with portts 52 which are immediately to the underside of the piston 4S and communicate with an enlarged counterbore 53 in the head 45 so that as it travels rightwardly in the cylinder 30, the hydraulic fluid is taken in at the head end of the bore and is expelled into the rod end of the cylinder to permit the rightward travel of the piston.

The piston 48 is also provided with several passages 54 connecting the rod end thereof with the head end, with each passage being provided with a check valve. This arrangement permits relatively free flow therethrough from the rod end of the piston 4S to the head end upon the leftward movement of the piston so as to facilitate the restoration of the impact absorbing device to normal position under the force exerted by the expanding spring 40.

A tapered flow metering pin 58 is secured as by welding to the inner face of the head 32 and positioned so as to enter the bore 50 in the piston rod 38% as the piston 48 moves rightwardly in the cylinder 30. The taper on the pin 58 is such as constantly to reduce the capacity of the open end of the bore Si) and thereby to diminish the outflow rate from the cylinder 30 and to increase the flow restriction. By the time piston 48 has reached the head 32, the open end of the bore 5()` is substantially closed.

The piston rod 38 extends into the reservoir 34 through appropriate packing 60 and is seated in a recess 62 formed on the inner face of the reservoir head 36. A piston rod is affixed to the reservoir head 36 by a bolt 64 or similar securing means. Thus the piston rod 38 and reservoir 34 move as a unit.

A group of minimum ow restriction ports 66 communcate the interior of the reservoir with the bore 50 through the piston rod 38, thereby placing the interior of the reservoir 34 in communication with the head end of the cylinder 39].

-The reservoir 34 is substantially filled with a plurality of hollow rings 68, four being shown. The rings 68 are sealed to contain air therein and are made of neoprene, oil resistant rubber, or similar material. When the hydraulic fluid is expelled from the head end of the cylinder 3i) through the bore 50 and ports 66, the reservoir becomes overlled with fluid due to the displacement by the rod 38, thereby collapsing the rings 68 against the pressure of the air contained therein. As seen in FIGS. 3 and 4 the rings 68 are compressed outwardly against the inner wall of the reservoir 34. f

The piston rod 38 has its exterior surface between the cylinder 30 and the reservoir 34 protected by a bellowslike boot 70 which is secured to the rod end head 45 of the cylinder and that portion of the reservoir which faces the cylinder. The hydraulic cushion is charged with uid through a suitable fitting 71 in the cylinder head 32.

In normal position the spring 40 holds the cylinder head 32 and the reservoir head 36 against the center sill lugs 42 and the underframe stop members 44. Should the car receive an impact from the left end (FIGS. 1 and 3) the center sill 12 will be moved rightwardly within the frame sill 14. The lugs 42 abutted against the reservoir head 36 will move the reservoir 34 toward the piston 30 whose head 32 Will be maintained against the underframe stop 44. The pin 58 enters the bore 50 for the purpose of metering the outflow of hydraulic uid from the head end of the cylinder 30, thereby increasing the resistance to piston travel rightwardly and a greater absorption of the impact. Fluid is expelled through the bore 50, the ports 52 behind the piston 48 to the counterbore 53 to permit initial piston travel and through the ports 66 into the reservoir 34. This excess fluid will compress the doughnut-like rings 68 against the pressure of the air therein, further giving resistance to the apparatus for absorption of the impact.

After the impact has been absorbed and the system returns to normal, the spring 40 expands, moving the reservoir 34 and cylinder 30 apart. As this occurs, the cylinder head 32 engages the center sill lugs 42 and the reservoir 34 is engaged by the stop frame member 44. The hydraulic fluid is transferred from the rod end of the cylinder to the head end through the ports 52 and passage 50 and also trnough the piston passages 54 past the check valves S6 which open to accommodate this iiow. This greater capacity permits the system to be restored to normal position with less restriction than present during collapsing of the cushion. The doughnut-like rings 68 also expand to their normal position, expelling tiuid from the reservoir 34 through the ports 66 and the bore 50 to the cylinder 30.

The same operation takes place if the impact is from the right end, in which case the lugs 42 would move the cylinder toward the reservoir and the left stop frame member 44 would be held against the head 36 of the reservoir 34 (FIG. 5).

From the foregoing specification it will be appreciated that the objectives which were set forth for this invention at the outset hereof are fully attained by the structure disclosed.

While a preferred embodiment of the invention has been shown and described, it will be apparent that numerous modifications and variations thereof may be made therein without departing from the underlying principles of the invention. It is therefore desired, by the following claims, to include Within the scope of the invention all such variations and modifications by which substantially the results of the invention may be obtained through the use of substantially the same or equivalent means.

What is claimed as new and desired to be secured by United States Letters Patent is:

1. In an impact absorbing apparatus for interposition between the draft vgear and the lading in a railway car of the type having a buff and draft center sill and a lading supporting frame mounted for movement relative to each other, the apparatus having a pair of heads normally abutted against stop lugs carried on the center sill and force transmitting stops carried on the lading supporting frame, and a spring urging the heads toward normal position, the improvement comprising, a cylinder mounting one of the heads, a fluid reservoir mounting the other of the heads, a piston slidable in said cylinder, a piston rod connected to said piston and to said fluid reservoir, a bore through said piston rod open to the head end of the cylinder, first ports in said piston rod connecting said bore with said reservoir, second ports in said piston rod connecting said bore with the rod end of said cylinder, check valve controlled passages through said piston permitting uid ilow only from the rod end to the head end of said cylinder, a tapered flow metering pin in said cylinder adapted to enter said piston rod bore to restrict increasingly huid flow therethrough during an impact absorbing movement of the piston in the cylinder, and a plurality of air filled compressible hollow rings substantially filling said reservoir when the impact absorbing apparatus is in extended position and adapted to be compressed upon the transfer of uid from the head end of the cylinder to the reservoir.

2. The impact absorbing apparatus as set forth in claim 1, wherein said hollow rings are of round transverse section.

3. The impact absorbing apparatus as .set forth in claim 1, wherein said hollow rings are of rectangular transverse section.

References Cited UNITED STATES PATENTS 2,856,035 9/1958 Rohacs 188-100 6 Zanow et al. 213-43 Ellis 18S-100 Brown et al. 188-88 Price et al 213-8 Price et al. 213-43 ARTHUR L. LA POINT, Primary Examiner.

D. E. HOFFMAN, Examiner. 

1. IN AN IMPACT ABSORBING APPARATUS FOR INTERPOSITIION BETWEEN THE DRAFT GEAR AND THE LADING IN A RAILWAY CAR OF THE TYPE HAVING A BUFF AND A DRAFT CENTER SILL AND A LADING SUPPORTING FRAME MOUNTED FOR MOVEMENT RELATIVE TO EACH OTHER, THE APPARATUS HAVING A PAIR OF HEADS NORMALLY ABUTTED AGAINST STOP LUGS CARRIED ON THE CENTER SILL AND FORCE TRANSMITTING STOPS CARRIED ON THE LADING SUPPORTING FRAME, AND A SPRING URGING THE HEADS TOWARD NORMAL POSITION, THE IMPROVEMENT COMPRISING, A CYLINDER MOUNTING ONE OF THE HEADS, A FLUID RESERVOIR MOUNTING THE OTHER OF THE HEADS, A PISTON SLIDABLE IN SAID CYLINDER, A PIATON ROD CONNECTED TO SAID PISTON AND TO SAID FLUID RESERVOIR, A BORE THROUGH SAID PISTON ROD OPEN TO THE HEAD END OF THE CYLINDER, FIRST PORTS IN SAID PISTON ROD CONNECTING SAID BORE WITH SAID RESERVOIR, SECOND PORTS IN SAID PISTON ROD CONNECTING SAID BORE WITH THE ROD END OF SAID CYLINDER, CHECK VALVE CONTROLLED PASSAGES THROUGH SAID PISTON PERMITTING FLUID FLOW ONLY FROM THE ROD END TO THE HEAD END OF SAID CYLINDER, A TAPERED FLOW METERING PIN IN SAID CYLINDER ADAPTED TO ENTER SAID PISTON ROD BORE TO RESTRICT INCREASINGLY FLUID FLOW THERETHROUGH DURING AN IMPACT ABSORBING MOVEMENT OF THE PISTON IN THE CYLINDER, AND A PLURALITY OF AIR FILLED COMPRESSIBLE HOLLOW RINGS SUBSTANTIALLY FILLING SAID RESERVOIR WHEN THE IMPACT ABSORBING APPARATUS IS IN EXTENDED POSITION AND ADAPTED TO BE COMPRESSED UPON THE TRANSFER OF FLUID FROM THE HEAD END OF THE CYLINDER TO THE RESERVOIR. 